Another Century's Episode 2 (Challenge Run): Op-14 Retake the New Submarine
So, underwater stages are pretty rare in this game, but most units are slowed down by being underwater, so it's important to plan around them. I know for sure that Antibodies (Brain Powerd units) and Aura Battlers are unaffected by water, and I think the Aestivalis Ground Frame also works underwater as normal. Oddly enough, Buster Ark doesn't work well underwater normally, but apparently the game might be cheating here to allow Marina to be a tougher boss.
Challenge Rules:
ACE Difficulty
No stat upgrades (units have base stats for the whole game)
Special/Combo upgrades only on units that get Custom Upgrades (like the Dragonar units)
Reuse units/forms only when necessary (chain missions count as one use)
Another Century's Episode 2 is a 2006 follow-up/sequel to the original game, produced by Banpresto and developed by From Software. ACE 2 takes the fanfiction-style crossover narrative of Super Robot Wars and combines it with an arcade shooter style action game, likely inspired by games like Virtual On. Featuring machines and characters from 14 different anime series in addition to original designs, ACE 2 is a solid improvement on the baseline established by the original Another Century's Episode.
